The main goal of this article is to analyze the effectiveness' dilemmas of government intelligence activities. Exploring the literature on intelligence failures and strategic surprise, we move towards a little explored field on Brazilian Intelligence Studies: the cognitive aspects of intelligence analysts and the relations between the political community and the intelligence community. First we balance the challenges of evaluating government intelligence as public policy, particularly regarding the effectiveness dimension. In the second session, we discuss the main cognitive biases and heuristics that can occur during intelligence analysis. The third section discusses the typical relational tensions between the political sphere and the intelligence community and how that relationship affects the final result of intelligence activity. In the concluding remarks, we point to the limits and possibilities of organizational and procedural reforms on the effectiveness of intelligence systems.